3 Bugfixes. (And probably new bugs. :))
5 The rule matching engine got converted from a rule list to a token
6 array which reduced the in-memory rules representation of a full
7 featured distros with thousends of rules from 1.2MB to 0.17 MB.
9 The limit of 5 ENV and ATTR matches, and a single instance for most
10 other keys per rule is gone with the new parser.
12 The NAME assignment is no longer special cased. If later rules assign
13 a NAME value again, the former value will be overwritten. As usual
14 for most other keys, the NAME value can be protected by doing a final
15 assignment with NAME:="<value>".
17 Many thanks to Alan Jenkins for finding and optimizing some of the
18 computing expensive parts.
24 Kernel devices and device nodes are connected now by reverse indizes in
25 /sys and /dev. A device number retrieved by a stat() or similar, the
26 kernel device directory can be found by looking up:
27 /sys/dev/{block,char}/<maj>:<min>
28 and the device node of the same device by looking up:
29 /dev/{block,char}/<maj>:<min>
33 Fix recently introduced bug, which caused a compilation without large
34 file support, where vol_id does not recognize raid signatures at the end
37 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
38 Seems some kernel versions prevent the creation of the ieee-* links,
39 so people used the scsi-* link which disappeared now.
41 More libudev work. Almost all udevadm functionality comes from libudev
44 udevadm trigger has a new option --type, which allows to trigger events
45 for "devices", for "subsystems", or "failed" devices. The old option
46 --retry-failed" still works, but is no longer mentioned in the man page.
52 The udevadm info --device-id-of-file= output has changed to use
53 the obvious format. Possible current users should use the --export
54 option which is not affected.
56 The old udev commands symlinks to udevadm are not installed, if
57 these symlinks are used, a warning is printed.
63 Optical drive's media is no longer probed for raid signatures,
64 reading the end of the device causes some devices to malfunction.
65 Also the offset of the last session found is used now to probe
68 The volume_id library got a major version number update to 1,
69 some deprecated functions are removed.
71 A shared library "libudev" gets installed now to provide access
72 to udev device information. DeviceKit, the successor of HAL, will
73 need this library to access the udev database and search sysfs for
75 The library is currently in an experimental state, also the API is
76 expected to change, as long as the DeviceKit integration is not
81 We use ./configure now. See INSTALL for details. Current
84 "/usr" - prefix for man pages, include files
86 "" - the root filesystem, prefix for libs and binaries
90 "lib" - directory name for libraries, not a path name
91 multilib 64bit systems may use "lib64" instead of "lib"
93 compile-in verbose debug messages
95 disable all logging and compile-out all log strings
97 link against SELInux libraries, to set the expected context
100 In the default rules, the group "disk" gets permissions 0660 instead
101 of 0640. One small step closer to unify distro rules. Some day, all
102 distros hopefully end up with the same set of rules.
104 No symlinks to udevadm are installed anymore, if they are still needed,
105 they should be provided by the package.
111 Default udev rules, which are not supposed to be edited by the user, should
112 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
113 the udev package and will be replaced with an update. Udev will pick up rule
115 /lib/udev/rules.d/ - default installed rules
116 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
117 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
118 It does not matter in which directory a rule file lives, all files are sorted
121 To help creating /dev/root, we have now:
122 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
125 In case the current --device-id-of-file is already used, please switch to
126 the --export format version, it saves the output parsing and the old
127 format will be changed to use ':' as a separator, like the format in the
132 Fix cdrom_id to properly recognize blank media.
138 Tape drive id-data is queried from /dev/bsg/* instead of the tape
139 nodes. This avoids rewinding tapes on open().
145 The symlinks udevcontrol and udevtrigger are no longer installed by
148 The scsi_id program does not depend on sysfs anymore. It can speak
149 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
150 data, which should solve some old problems with tape devices, where
151 we better do not open all tape device nodes to identify the device.
157 The cdrom_id program is replaced by an advanced version, which can
158 detect most common device types, and also properties of the inserted
159 media. This is part of moving some basic functionality from HAL into
160 udev (and the kernel).
166 The last WAIT_FOR_SYSFS rule is removed from the default rules.
168 The symlinks to udevadm for the debugging tools: udevmonitor and
169 udevtest are no longer created.
171 The symlinks to the udevadm man page for the old tool names are
174 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
175 should be prefixed with '@' to indicate that the path is not a
186 Udevstart is removed from the tree, it did not get installed for
187 a long time now, and is long replaced by trigger and settle.
193 All udev tools are merged into a single binary called udevadm.
194 The old names of the tools are built-in commands in udevadm now.
195 Symlinks to udevadm, with the names of the old tools, provide
196 the same functionality as the standalone tools. There is also
197 only a single udevadm.8 man page left for all tools.
199 Tools like mkinitramfs should be checked, if they need to include
200 udevadm in the list of files.
210 The etc/udev/rules.d/ directory now contains a default set of basic
211 udev rules. This initial version is the result of a rules file merge
212 of Fedora and openSUSE. For these both distros only a few specific
213 rules are left in their own file, named after the distro. Rules which
214 are optionally installed, because they are only valid for a specific
215 architecture, or rules for subsystems which are not always used are
216 in etc/udev/packages/.
222 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
223 actions by dynamically created rules.
225 SYMLINK=="<value>" matches agains the entries in the list of
226 currently defined symlinks. The links are not created in the
227 filesystem at that point in time, but the values can be matched.
229 RUN{ignore_error}+="<program>" will ignore any exit code from the
230 program and not record as a failed event.
236 Final merge of patches/features from the Ubuntu package.
242 Control characters in filesystem label strings are no longer silenty
243 removed, but hex-encoded, to be able to uniquely identify the device
244 by its symlink in /dev/disk/by-label/.
245 If libvolume_id is used by mount(8), LABEL= will work as expected,
246 if slashes or other characters are used in the label string.
248 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
249 can be specified now. The TEST key accepts an optional mode mask
250 TEST{0100}=="<is executable file>".
252 Scsi_id now supports a mode without expecting scsi-specific sysfs
253 entries to allow the extraction of cciss-device persistent properties.
259 In the future, we may see uuid's which are just simple character
260 strings (see the DDF Raid Specification). For that reason vol_id now
261 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
262 the creation of symlinks, the *_SAFE values ensure, that no control
263 or whitespace characters are used in the filename.
265 Possible users of libvolume_id, please use the volume_id_get_* functions.
266 The public struct will go away in a future release of the library.
272 Removal of useless extras/eventrecorder.sh.
282 The directory multiplexer for dev.d/ and hotplug.d are finally removed
283 from the udev package.
289 Symlinks can have priorities now, the priority is assigned to the device
290 and specified with OPTIONS="link_priority=100". Devices with higher
291 priorities overwrite the symlinks of devices with lower priorities.
292 If the device that currently owns the link, goes away, the symlink
293 will be removed, and recreated, pointing to the next device with the
294 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
295 more reliable, if multiple devices contain the same metadata and overwrite
298 The dasd_id program is removed from the udev tree, and dasdinfo, with the
299 needed rules, are part of the s390-tools now.
301 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
302 we may get the scsi sysfs mess fixed some day, and this will only catch
303 the devices we are looking for.
305 USB serial numbers for storage devices have the target:lun now appended,
306 to make it possibble to distinguish broken multi-lun devices with all
307 the same SCSI identifiers.
309 Note: The extra "run_directory" which searches and executes stuff in
310 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
311 with the next release. Make sure, that you don't use it anymore, or
312 provides your own implementation of that inefficient stuff.
313 We are tired of reports about a "slow udev", because these directories
314 contain stuff, that runs with _every_ event, instead of using rules,
315 that run programs only for the matching events.
325 DRIVER== will match only for devices that actually have a real
326 driver. DRIVERS== must be used, if parent devices should be
327 included in the match.
329 Libvolume_id's "linux_raid" detection needed another fix.
337 Add additional check to volume_id detection of via_raid, cause
338 some company decided to put a matching pattern all over the empty
339 storage area of their music players.
343 Fix path_id for SAS devices.
347 The udev daemon can be started with --debug-trace now, which will
348 execute all events serialized to get a chance to catch a possible
349 action that crashes the box.
351 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
352 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
353 are excluded from the warning. Referencing parent attributes directly
354 may break when something in the kernel driver model changes. Udev will
355 just find the attribute by walking up the parent chain.
357 Udevtrigger now sorts the list of devices depending on the device
358 dependency, so a "usb" device is triggered after the parent "pci"
363 Revert persistent-storage ata-serial '_' '-' replacement.
369 Udevtrigger can now filter the list of devices to be triggered. Matches
370 for subsystems or sysfs attributes can be specified.
372 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
373 zero-sized files to avoid pointing to /sys and confuse broken tools which
374 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
377 The rules and scripts to create udev rules for persistent network
378 devices and optical drives are in the extras/rules_generator directory
379 now. If you use something similar, please consider replacing your own
380 version with this, to share the support effort. The rule_generator
381 installs its own rules into /etc/udev/rules.d.
383 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
384 the rule_generator depends on cdrom_id to be called in an earlier rule.
390 Renaming of some key names (the old names still work):
391 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
392 (The behavior of the key DRIVER will change soon in one of the next
393 releases, to match only the event device, please switch to DRIVERS
394 instead. If DRIVER is used, it will behave like DRIVERS, but an error
396 With the new key names, we have a more consistent and simpler scheme.
397 We can match the properties of the event device only, with: KERNEL,
398 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
399 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
400 longer mentioned in the man page and should be switched in the rule
403 ATTR{file}="value" can be used now, to write to a sysfs file of the
404 event device. Instead of:
405 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
407 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
409 All the PHYSDEV* keys are deprecated and will be removed from a
411 PHYDEVPATH - is the path of a parent device and should not be
413 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
414 matched with SUBSYSTEMS==
415 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
416 Newer kernels will have DRIVER in the environment,
417 for older kernels udev puts in. Class device will
418 no longer carry this property of a parent and
419 DRIVERS== can be used to match such a parent value.
420 Note that ENV{DRIVER} is only available for a few bus devices, where
421 the driver is already bound at device event time. On coldplug, the
422 events for a lot devices are already bound to a driver, and they will have
423 that value set. But on hotplug, at the time the kernel creates the device,
424 it can't know what driver may claim the device after that, therefore
425 in most cases it will be empty.
427 Failed events should now be re-triggered with:
428 udevtrigger --retry-failed.
429 Please switch to this command, so we keep the details of the /dev/.udev/failed/
430 files private to the udev tools. We may need to switch the current symlink
431 target, cause some obviously broken tools try to scan all files in /dev
432 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
433 million times. This takes ages on slow boxes.
435 The udevinfo attribute walk (-a) now works with giving a device node
436 name (-n) instead of a devpath (-p). The query now always works, also when
437 no database file was created by udev.
439 The built-in /etc/passwd /etc/group parser is removed, we always depend on
440 getpwnam() and getgrnam() now. One of the next releases will depend on
441 fnmatch() and may use getopt_long().
445 Bugfixes and small improvements.
449 Fix path_id for recent kernels.
455 Added support for swapping network interface names, by temporarily
456 renaming the device and wait for the target name to become free.
460 The built-in MODALIAS key and substitution is removed.
464 The binary firmware helper is replaced by the usual simple
465 shell script. Udevsend is removed from the tree.
473 Some more keys require the correct use of '==' and '=' depending
474 on the kind of operation beeing an assignment or a match. Rules
475 with invalid operations are skipped and logged to syslog. Please
476 test with udevtest if the parsing of your rules throws errors and
477 fix possibly broken rules.
481 Provide "udevsettle" to wait for all current udev events to finish.
482 It also watches the current kernel netlink queue by comparing the
483 even sequence number to make sure that there are no current pending
484 events that have not already arrived in the daemon.
488 Fix rule to skip persistent rules for removable IDE devices, which
489 also skipped optical IDE drives.
491 All *_id program are installed in /lib/udev/ by default now.
493 No binary is stripped anymore as this should be done in the
494 packaging process and not at build time.
496 libvolume_id is provided as a shared library now and vol_id is
497 linked against it. Also one of the next HAL versions will require
498 this library, and the HAL build process will also require the
499 header file to be installed. The copy of the same code in HAL will
500 be removed to have only a single copy left on the system.
504 Add persistent links for SCSI tapes. The rules file is renamed
505 to 60-persistent-storage.rules.
507 Create persistent path for usb devices. Can be used for all sorts
508 of devices that can't be distinguished by other properties like
509 multiple identical keyboards and mice connected to the same box.
511 Provide "udevtrigger" program to request events on coldplug. The
512 shell script is much too slow with thousends of devices.
516 Fix persistent disk rules to exclude removable IDE drives.
518 Warn if %e, $modalias or MODALIAS is used.
522 Fix queue export, which wasn't correct for subsequent add/remove
523 events for the same device.
527 Fix cramfs detection on big endian.
529 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
534 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
535 attributes were only checked at the parent device that matched the
536 by BUS requested subsystem. Fix it to also look at the device we
537 received the event for.
539 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
544 Fix a bug where NAME="" would prevent RUN from beeing executed.
546 RUN="/bin/program" does not longer automatically add the subsystem
547 as the first parameter. This is from the days of /sbin/hotplug
548 which is dead now and it's just confusing to need to add a space at
549 the end of the program name to prevent this.
550 If you use rules that need the subsystem as the first parameter,
551 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
552 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
556 The udev man page has moved to udev(7) as it does not describe a command
557 anymore. The programs udev, udevstart and udevsend are no longer installed
558 by default and must be copied manually, if they should be installed or
559 included in a package.
561 Fix a bug where "ignore_device" could run earlier collected RUN keys before
562 the ignore rule was applied.
564 More preparation for future sysfs changes. usb_id and scsi_id no longer
565 depend on a magic order of devices in the /devices chain. Specific devices
566 should be requested by their subsytem.
568 This will always find the scsi parent device without depending on a specific
570 dev = sysfs_device_get(devpath);
571 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
573 The "device" link in the current sysfs layout will be automatically
574 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
575 parent in the devpath. If a device is requested by it's symlink, like all
576 class devices in the new sysfs layout will look like, it gets automatically
577 resolved and substituted with the real devpath and not the symlink path.
580 A similar logic must be applied to _all_ sysfs users, including
581 scripts, that search along parent devices in sysfs. The explicit use of
582 the "device" link must be avoided. With the future sysfs layout all
583 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
584 back to the "class" or the "bus". The layout of the parent devices in
585 /devices is not necessarily expected to be stable across kernel releases and
586 searching for parents by their subsystem should make sysfs users tolerant
587 for changed parent chains.
591 Prepare udev to work with the experimental kernel patch, that moves
592 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
594 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
595 moving the class devices to /sys/devices.
597 Thanks again to Marco for help finding a hopefully nice compromise
598 to make %b simpler and working again.
602 Complete removal of libsysfs, replaced by simple helper functions
603 which are much simpler and a bit faster. The udev daemon operatesentirely
604 on event parameters and does not use sysfs for simple rules anymore.
605 Please report any new bugs/problems, that may be caused by this big
606 change. They will be fixed immediately.
608 The enumeration format character '%e' is deprecated and will be
609 removed sometimes from a future udev version. It never worked correctly
610 outside of udevstart, so we can't use it with the new parallel
611 coldplug. A simple enumeration is as useless as the devfs naming
612 scheme, just get rid of both if you still use it.
614 MODALIAS and $modalias is not needed and will be removed from one of
615 the next udev versions, replace it in all rules with ENV{MODALIAS} or
616 the sysfs "modalias" value.
618 Thanks a lot to Marco for all his help on finding and fixing bugs.
622 Let scsi_id request libata drive serial numbers from page 0x80.
624 Renamed etc/udev/persistent.rules to persistent-disk.rules and
625 added /dev/disk/by-name/* for device mapper device names.
627 Removed %e from the man page. It never worked reliably outside
628 of udevstart and udevstart is no longer recommended to use.
632 Symlinks are now exported to the event environment. Hopefully it's no
633 longer needed to run udevinfo from an event process, like it was
634 mentioned on the hotplug list:
635 UDEV [1134776873.702967] add@/block/sdb
638 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
642 Fix a problem if udevsend is used as the hotplug handler and tries to use
643 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
644 and this kind of problems will hopefully go away soon.
648 All built-in logic to work around bad sysfs timing is removed with this
649 version. The need to wait for sysfs files is almost fixed with a kernel
650 version that doesn't work with this udev version anyway. Until we fix
651 the timing of the "bus" link creation, the former integrated logic should
652 be emulated by a rule placed before all other rules:
653 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
655 The option "udev_db" does no longer exist. All udev state will be in
656 /$udev_root/.udev/ now, there is no longer an option to set this
658 If the init script or something else used this value, just depend on
659 this hardcoded path. But remember _all_content_ of this directory is
660 still private to udev and can change at any time.
662 Default location for rule sripts and helper programs is now: /lib/udev/.
663 Everything that is not useful on the commandline should go into this
664 directory. Some of the helpers in the extras folder are installed there
665 now. The rules need to be changed, to find the helpers there.
667 Also /lib/udev/devices is recommended as a directory where packages or
668 the user can place real device nodes, which get copied over to /dev at
669 every boot. This should replace the various solutions with custom config
672 Udevsend does no longer start the udev daemon. This must be done with
673 the init script that prepares /dev on tmpfs and creates the initial nodes,
674 before starting the daemon.
678 Silent a too verbose error logging for the old hotplug.d/ dev.d/
681 The copy of klibc is removed. A systemwide installed version of klibc
682 should be used to build a klibc udev now.
686 NAME="" will not create any nodes, but execute RUN keys. To completely
687 ignore an event the OPTION "ignore_device" should be used.
689 After removal of the reorder queue, events with a TIMEOUT can be executed
690 without any queuing now.
694 Fixed bug in udevd, if inotify is not available. We depend on netlink
695 uevents now, kernels without that event source will not work with that
696 version of udev anymore.
700 The rule parsing happens now in the daemon once at startup, all udev
701 event processes inherit the already parsed rules from the daemon.
702 It is shipped with SUSE10.0 and reduces heavily the system load at
703 startup. The option to save precompiled rules and let the udev process
704 pick the them up is removed, as it's no longer needed.
706 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
707 device. Libsysfs is changed to "translate" the requested link into the
708 real device path, as it would happen with the hotplug event. Otherwise
709 device removal and the udev database will not work.
711 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
714 A few improvements for vol_id, the filesytem probing code.
718 Fix a stupid typo in extras/run_directory for "make install".
720 scsi_id creates the temporary devnode now in /dev for usage with a
721 non-writable /tmp directory.
723 The uevent kernel socket buffer can carry app. 50.000 events now,
724 let's see who can break this again. :)
726 The upcoming kernel will have a new input driver core integration.
727 Some class devices are now symlinks to the real device. libsysfs
728 needs a fix for this to work correctly. Udevstart of older udev
729 versions will _not_ create these devices!
733 Fix a 'install' target in the Makefile, that prevents EXTRAS from
738 A bunch of mostly trivial bugfixes. From now on no node name or
739 symlink name can contain any character than plain whitelisted ascii
740 characters or validated utf8 byte-streams. This is needed for the
741 /dev/disk/by-label/* links, because we import untrusted data and
742 export it to the filesystem.
746 More bugfixes. If udevd was started from the kernel, we don't
747 have stdin/stdout/stderr, which broke the forked tools in some
752 Bugfix. udevstart event ordering was broken for a long time.
753 The new run_program() uncovered it, because /dev/null was not
754 available while we try to run external programs.
755 Now udevstart should create it before we run anything.
759 Minor bugfixes and some distro rules updates. If you don't have the
760 persistent disk rules in /dev/disk/by-*/* on your distro, just
761 grab it from here. :)
765 We can use socket communication now to pass events from udev to
767 RUN+="socket:/org/freedesktop/hal/udev_event"
768 will pass the whole udev event to the HAL daemon without the need
769 for a forked helper. (See ChangeLog for udevmonitor, as an example)
773 Mostly bugfixes and see ChangeLog.
775 The test for the existence of an environment value should be
777 ENV{KEY}=="*" to ENV{KEY}=="?*"
778 because "*" will not fail anymore, if the key does not exist or
783 Bugfixes and a few tweaks described in the ChangeLog.
787 Mostly a Bugfix release.
789 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
790 timing with custom rules.
794 We changed the internal rule storage format. Our large rule files took
795 2 MB of RAM, with the change we are down to 99kB.
797 If the device-node has been created with default name and no symlink or
798 options are to remenber, it is not longer stored in the udevdb. HAL will
799 need to be updated to work correctly with that change.
801 To overrride optimization flags, OPTFLAGS may be used now.
809 Major changes happened with this release. The goal is to take over the
810 complete kernel-event handling and provide a more efficient way to dispatch
811 kernel events. Replacing most of the current shell script logic and the
812 kernel forked helper with a netlink-daemon and a rule-based event handling.
814 o udevd listens to netlink events now. The first valid netlink event
815 will make udevd ignore any message from udevsend that contains a
816 SEQNUM, to avoid duplicate events. The forked events can be disabled
818 echo "" > /proc/sys/kernel/hotplug
819 For full support, the broken input-subsytem needs to be fixed, not to
820 bypass the driver core.
822 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
823 removed from udev itself and must be emulated by calling small
824 helper binaries provided in the extras folder:
825 make EXTRAS=extras/run_directory/
826 will build udev_run_devd and udev_run_hotplugd, which can be called
827 from a rule if needed:
828 RUN+="/sbin/udev_run_hotplugd"
829 The recommended way to handle this is to convert all the calls from
830 the directories to explicit udev rules and get completely rid of the
831 multiplexing. (To catch a ttyUSB event, you now no longer need to
832 fork and exit 300 tty script instances you are not interested in, it
833 is just one rule that matches exactly the device.)
835 o udev handles now _all_ events not just events for class and block
836 devices, this way it is possible to control the complete event
837 behavior with udev rules. Especially useful for rules like:
838 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
840 o As used in the modalias rule, udev supports now textual
841 substitution placeholder along with the usual format chars. This
842 needs to be documented, for now it's only visible in udev_rules_parse.c.
844 o The rule keys support now more operations. This is documented in the
845 man page. It is possible to add values to list-keys like the SYMLINK
846 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
847 Also "final"-assignments are supported by using KEY:="value", which will
848 prevent changing the key by any later rule.
850 o kernel 2.6.12 has the "detached_state" attribute removed from
851 sysfs, which was used to recognize sysfs population. We switched that
852 to wait for the "bus" link, which is only available in kernels after 2.6.11.
853 Running this udev version on older kernels may cause a short delay for
856 o To provide infrastructure for persistent device naming, the id programs:
857 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
858 to export the probed data in environment key format:
859 pim:~ # /sbin/ata_id --export /dev/hda
860 ID_MODEL=HTS726060M9AT00
861 ID_SERIAL=MRH401M4G6UM9B
865 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
866 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
869 kay@pim:~> tree /dev/disk
872 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
873 | `-- IBM-Memory_Key -> ../../sda
875 | |-- swap -> ../../hda1
876 | |-- date -> ../../sda1
877 | `-- home -> ../../hda3
879 |-- 2E08712B0870F2E7 -> ../../hda3
880 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
881 |-- E845-7A89 -> ../../sda1
882 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
884 The IMPORT= operation will import these keys in the environment and make
885 it available for later PROGRAM= and RUN= executed programs. The keys are
886 also stored in the udevdb and can be queried from there with one of the
889 o A few binaries are silently added to the repository, which can be used
890 to replay kernel events from initramfs instead of using coldplug. udevd
891 can be instructed now to queue-up events while the stored events from
892 initramfs are filled into the udevd-queue. This code is still under
893 development and there is no documentation now besides the code itself.
894 The additional binaries get compiled, but are not installed by default.
896 o There is also a temporary fix for a performance problem where too many
897 events happen in parallel and every event needs to parse the rules.
898 udev can now read precompiled rules stored on disk. This is likely to be
899 replaced by a more elegant solution in a future udev version.
903 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
904 Fix for libsysfs not to expect this file was added.
908 All rules are applied now, but only the first matching rule with a NAME-key
909 will be applied. All later rules with NAME-key are completely ignored. This
910 way system supplied symlinks or permissions gets applied to user-defined
914 Please check your rules setup, if you may need to add OPTIONS="last_rule"
915 to some rules, to keep the old behavior.
917 The rules are read on "remove"-events too. That makes is possible to match
918 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
919 instruct udev to ignore an event (OPTIONS="ignore_device").
920 The new ACTION-key may be used to let a rule act only at a "remove"-event.
922 The new RUN-key supports rule-based execution of programs after device-node
923 handling. This is meant as a general replacement for the dev.d/-directories
924 to give fine grained control over the execution of programs.
926 The %s{}-sysfs format char replacement values are searched at any of the
927 devices in the device chain now, not only at the class-device.
929 We support log priority levels now. The value udev_log in udev.conf is used
930 to determine what is printed to syslog. This makes it possible to
931 run a version with compiled-in debug messages in a production environment
932 which is sometimes needed to find a bug.
933 It is still possible to supress the inclusion of _any_ syslog usage with
934 USE_LOG=false to create the smallest possible binaries if needed.
935 The configured udev_log value can be overridden with the environment variable
940 Possible use of a system-wide klibc:
941 make USE_KLIBC=true KLCC=/usr/bin/klcc all
942 will link against an external klibc and our own version will be ignored.
946 We support an unlimited count of symlinks now.
948 If USE_STATIC=true is passed to a glibc build, we link statically and use
949 a built-in userdb parser to resolve user and group names.
951 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
952 we walk up the chain of physical devices to find a match.
954 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
955 easy to skip certain attribute matches without composing rules with weird
956 character class negations like:
957 KERNEL="[!s][!c][!d]*"
958 this can now be replaced with:
960 The current simple '=' is still supported, and should work as it does today,
961 but existing rules should be converted if possible, to be better readable.
963 We have new ENV{}== key now, to match against a maximum of 5 environment
966 udevstart is its own binary again, because we don't need co carry this araound
967 with every forked event.
~ianmdlvl / elogind.git / blob